Theoretical analysis of the steam pressure exchange ejector for an automotive air conditioning application.

摘要

The project conducted at The George Washington University is a computer simulation and theoretical analysis of the steam pressure exchange ejector air conditioning system for an automobile at various ejector efficiencies and modeled using the turbomachinery analog. The turbomachinery analog is an idealization of the pressure exchange ejector for thermally energized air conditioning applications. The system is well suited for capturing waste heat from the internal combustion engine exhaust. In particular, the ejector automotive air conditioning system is designed to replace the belt driven compressor and reduce the gasoline consumed and corresponding greenhouse gas emissions. The research involves comparing numerical results from an existing conventional automotive air conditioning system using refrigerant R-134a on an average midsized sedan with the steam pressure exchange ejector air conditioning system on the 2005 BMW 530i midsize sedan. The new air conditioning system contains the ejector and an additional loop consisting of exhaust gas heat exchangers, and a pump in exchange for the compressor. The inclusion of the ejector into the system will cause modifications in the system component design and size, especially in the condenser. Computer simulations consist of an ideal system analysis along with results from a more realistic system based on previous ejector efficiencies, system parameters, and generalized dissipations from equipment. Tests are conducted through computer simulations using MATLAB/Simulink. Further investigation compares the performance and capabilities of the conventional ejector with the pressure exchange ejector to better understand the fundamental differences.